Hosting Websites

I currently maintain 50 websites for people. A lot of these people I never seem to hear from anymore. none of these people are helping me pay for my hosting etc. which when all added up is over a thousand dollars a year between the base hosting and paying for the domain names.
If I am hosting your website, and I have not heard from you in a while, and I do not hear from you by the end of March I shall cancel the website.